David Millar was sitting on his couch in Biarritz, France – oddly calm. Moments earlier, a Paris drug squad had tracked him down and entered his home, guns drawn, searching for evidence that one of the world’s top young cyclists used performance-enhancing drugs. No matter. Mr. Millar, who had taken blood-doping stimulants a year earlier, decided to go clean after winning the 2003 world championship individual time trial.

As the agents approached his bedroom, though, Millar panicked. He remembered that he had stashed his last two syringes in a watch box on the bookshelf. “I had this flash – there’s something in the bookcase,” he recalls. Moments later, Millar was hauled off to jail – in handcuffs.

Today Millar has become a poster child for a budding movement to clean up a sport that has arguably been more damaged than any other by doping. After being stripped of his world championship and banned by the British cycling federation from the sport for two years, he is back with a team that is pioneering new methods to prove its athletes are drug-free.

And they’re putting in a respectable showing. His Garmin-Chipotle squad led the team standings in the early stages of this year’s Tour de France, and teammate Christian Vande Velde is now ranked third. While some on the cycling circuit fault Millar for trying to capitalize on his conversion, his team’s self-policing approach has become a model that an increasing number inside and outside the sport are emulating.

Millar himself has rediscovered his passion for cycling. During his darkest days, he says he felt like he was “living a lie.” When he was arrested and briefly jailed, he decided, “OK, that’s it – I’m going to break free.”

Now he’s reveling in the purity of the sport again. “The process is more fun,” he says in a telephone interview from his home in Girona, Spain. “I enjoy the training, enjoy the work. It’s back to the way it was when I was a kid.”
•••Millar considered going to college to study art, but instead became a professional cyclist. While in his late teens, the lean tall Scot, who was born on the island of Malta and grew up in Hong Kong, supported his nascent racing career by working nights at a supermarket and training during the day. He won his first major race at age 20.

In 1997, he got a big break: The professional team Cofidis hired him. Yet the easygoing Millar had no idea what he was getting into.

“I got into professional cycling bright-eyed and bushy-tailed, totally naive to the fact that doping existed,” says Millar. Within a few months, he realized that guys around him were taking illegal drugs. “It was a total culture shock – I was entering this dark, secretive world.”

He was a good rider without drugs, but not good enough to guarantee results that would maintain his six-figure salary and comfortable lifestyle. In 2001, he went into the Tour de France having raced nearly 1 in 3 days for the past six months.

Exhausted, he withdrew. It was then that a team manager urged him to go stay with an older rider in Italy. Shortly thereafter, Millar started taking drugs.“It was attractive to the team, and became attractive to me as well,” he says. “My values and ethics got chipped away over time.”

Doping did make his life easier. In cycling, a 2 percent boost in performance can mean the difference between winning and losing. Plus, he says, the drugs enhanced his endurance and reduced his body’s recovery time. “I was doing it purely for the results – I was not doing it for the voyage,” he says. “When you win, it’s pure relief, because it justifies the risk you took.”

Other athletes echo how intense the pressures of operating at the top can be. US decathlete Bryan Clay calls it a “scary and lonely place.” “If all I wanted in the world was to win the gold medal and set a world record and make lots of money, I can almost guarantee you that I would be on steroids,” says Mr. Clay, a 2008 Olympian who is participating in a pilot US antidoping program based on similar principles as Garmin-Chipotle’s. “You’d never want that to end. You’d just want to be on top forever. [But] I want to be the best without sacrificing who I am.”

That may be the larger point in the end: Do drugs at some point change who we are? As pill use of all kinds becomes more pervasive, artificial enhancements, both legal and illegal, are increasingly seen as a legitimate way to boost one’s inherent abilities. We take everything from Botox for a wrinkle-free face to Viagra for better romance. What’s wrong with a little oxygen-enhancement if you’re a cyclist?

“People want an easier way to deal with their lives,” says Oliver Catlin, vice president of an antidoping research firm in Los Angeles. “That’s why athletes turn to steroids. It’s looking for external ways to improve their identity.”

Once a cyclist turns to doping, stopping isn’t as simple as “just saying no.” Millar says many riders “are married, have kids, are heroes in their villages. The people around them believe in them. They don’t see that if you tell the truth and explain how it happened, people do understand.”

Millar had to endure the worst before he could climb out of his own slough. When the drug agents came to his house on the fateful day in 2004, he wasn’t home. He was dining out. They hauled him home to conduct the search. The agents had been investigating a doping ring involving some of Millar’s teammates. The two syringes they found were left over from a time when the cyclist had used the endurance-boosting drug erythropoeitin.

“I realized I was going to lose everything – the house I’d built the expensive car I’d ordered – all this material stuff was gone,” recalls Millar. “But when I was lying there, I realized it didn’t matter. To be free and able to get out of that was almost a relief.”

For the next few months, Millar indulged in “pure escapism.” He wanted to get as far away from cycling as possible. “I was sleeping on my sister’s floor,” he says. “I had my head in the sand.” Eventually, he realized how fortunate he had been to be an athlete and decided to stage a comeback – clean. He’d also come to sympathize with the disillusionment fans were feeling about cycling. “It became my role to be a voice that’s seen both sides,” he says.
•••When Millar finished his two-year ban, he wasn’t the only one that needed a resurrection. Cycling was reeling. Revelations of doping were rampant, and major European TV stations were pulling coverage of races.

Former rider Jonathan Vaughters thought it was time to clean up the sport from the inside. In 2007, his team, Slipstream Sports, launched an aggressive antidoping program administered independently by the Agency for Cycling Ethics in Los Angeles. Each athlete was tested with no advance notice at least every two weeks – 20 times more often than required under cycling rules. It yields a physiological profile that would make any drug-induced spike readily apparent.

Several other teams followed suit, and sponsors began to flock to this audacious cadre of riders who declared the importance of competing clean over winning. Last year, Millar signed on, bringing new clout to the group.

“We’re not afraid to fail,” says Steven Cozza, a member of the team, now called Garmin-Chipotle. “It’s 100 percent of you and nothing else that’s achieving. At the end of the day, that’s the most important thing.” Riders feel a shift on tour as well. “The whole attitude and talk in the peloton has changed,” says Mr. Cozza. “Everyone is believing you can win clean.”

Still, some critics believe Millar has cast the sport as too dirty and himself as savior. “There are some who say he’s spitting in the soup,” says Guy Andrews, editor of Rouleur, a British cycling magazine. “But I don’t think he’s pious about it. He’s very blunt and very honest.”

Actually, Millar believes that dopers represent a “minority” of riders. Yet he thinks it will take five to 10 years to clean up the sport’s image.“It has lost a little bit of magic,” he says. “They [the young riders] don’t deserve to pay for the errors I made or the errors my generation made. We’ve got to get back to the stories of individuals and that epicness.”

• The next installment in this series runs July 28. The first part ran July 14.